Automatic coupling system

ABSTRACT

In an automatic coupling system, a threaded quill is connected to a rotating and advancing mechanism by a slip coupling and is biased toward a drill pipe by a spring. In the use of the system, the quill is advanced toward the drill pipe and is simultaneously rotated with respect to the pipe. When the quill engages the pipe, it slips relative to the advancing and rotating mechanism against the action of the spring until a quill advance terminating switch is closed. The rotation of the quill is continued until the torque on the quill reaches a predetermined limit.

United States Patent 1 ,6 2,842

Bromell May 16, 1972 [541 AUTOMATIC COUPLING SYSTEM 1 2,887,920 5/1959Austin ..81/52.4 2,984,000 5/1961 McConnell ....81/52.4 X [72] Dallas2,972,388 2/1961 Thornburg.... ..166/77.5 x [73] Assignee: AutomaticDrilling Machines, Inc., Dallas, 3,191,450 6/1965 Wilson ..173/ 1.63 X

Tex.

22 F} d: A 14 1970 Primary Examiner-Ernest R. Purser l l e prAttorney-Richards, Harris & Hubbard [211 App]. No.: 28,344

57 ABSTRACT [52] US. Cl ..l73/l, 29/240, 166/775, I an automatic liystem, a threaded quill is connected 166/315 173/15 173/164 to arotating and advancing mechanism by a slip coupling and Int. Cl. itoward a a spring [n [he use of [he [58] Field of Search ..81/52.4,57.11, 57.33, 57.34, 81/5735; 173/1, 45,12, 21,164, 57,163,15; 175/27,52, 57, 85, 170; 166/775, 315; 29/240 system, the quill is advancedtoward the drill pipe and is simultaneously rotated with respect to thepipe. When the quill engages the pipe, it slips relative to theadvancing and rotating mechanism against the action of the spring untila quill ad- [56] References Cited vance terminating switch is closed.The rotation of the quill is UNITED STATES PATENTS continued until thetorque on the quill reaches a predetermined limit. 1,377,575 5/1921Greve ..173/57 2,762,403 9/1956 Ferm et a1 ..81/57.11 X 18 Claims, 5Drawing Figures TO HYDRAULIC HYDRAULIC CYLINDERS l8 PUMP MOTOR AND TTRANSMISSIJN ORQUE HYDRAULIC ENGINE 72 ASSEMBLY MONITOR PUMP "ZIIIIIPATENTEDMM 16 I972 SHEET 1 BF 2 7 TO HYDRAULIC HYDRAULIC CYLINDERS l8VALVE PUMP ENG'NE l4 78 a0 82 g" a4 74 76 22 MOTOR AND I TOR UETRANSMISSION Q HYDRAUL -----ENGINE ASSEMBLY MONITOR PUMP FIG 2 INVENTORRAYMOND J. BROME L L @W Wf QQ JM ATTORNEYS PATENTEnmmsmz 3,662,842

SHEET 2 OF 2 INVENTOR RAYMOND J. BROMELL Pal/1.94% WM ATTORNEYSAUTOMATIC COUPLING SYSTEM BACKGROUND OF THE INVENTION In the drillingindustry, drilling machines or rigs are employed to form oil wells andsimilar deep boreholes. As opposed to conventional rigs, automaticdrilling machines perform the various steps involved in forming aborehole without human intervention. Typically, this is accomplished bymeans of a drill head mounted in a drilling tower for vertical movementby hydraulic cylinders connected to the top of the tower.

In the use of an automatic drilling machine, the drill head is connectedto a drill bit through a string of drill pipe. The drill head rotatesthe drill string and the drillbit and thereby forms a borehole. As thedepth of the borehole increases, new sections of drill pipe are added tothe drill string. This is accomplished by disconnecting the drill headfrom the drill string, operating the hydraulic cylinders to raise thedrill head to the top of the tower, connecting a new section of pipe tothe drill head, and then connecting the new section to the drill string.

I-Iereto fore, the connection of the drill head to a new section ofdrill pipe has been a relatively slow operation, even in an automaticdrilling machine. This is because the drill head is connected to thepipe through a quill that is threadably engaged with the upper portionof the pipe. In order to threadably interengage the quill and the pipe,it has heretofore been necessary to rotate and advance the quill inaccordance with the lead of the threaded connection.

This invention relates to a method and apparatus whereby the drill headof an automatic drilling machine is attached to a section of drill pipein a rapid and efficient manner. The use of the invention permits theautomaticconnection of the drill head to a section of drill pipe withoutdanger of jamming or mutilating the threads of either the pipe or thequill, and without the necessity of accurately positioning the pipe.Furthermore, the use of the invention eliminates the application ofexcessive torque loads to the threaded connection between the quill andthe pipe, and thereby facilitates the subsequent removal of the quillfrom the pipe.

SUMMARY OF THE INVENTION In accordance with the preferred embodiment ofthe invention, an automatic coupling system includes a threaded memberthat is simultaneously advanced and rotated. The advance of the threadedmember continues until the threaded member contacts another threadedmember. Rotation continues until a threaded connection is formed.Preferably, the threaded member is spring biased and is rotated until apredetermined torquev is applied between the threaded members.

DESCRIPTION OF THE DRAWINGS A more complete understanding of theinvention may be had by referring to the following detailed descriptionwhen taken in conjunction with the drawings, wherein:

FIG. 1 is an illustration of an automatic drilling machine including anautomatic coupling system employing the present invention;

FIG. 2 is an enlarged sectional view illustrating the automatic couplingsystem of the automatic drilling machine shown in FIG. 1, and

FIGS. 3, 4 and 5 are illustrations of various steps in the operation ofthe automatic coupling system.

DETAILED DESCRIPTION Referring now to the drawings, and particularly toFIG. 1 thereof, there is shown an automatic drilling machine includingan automatic coupling system 12 employing the present invention. Theautomatic drilling machine 10 includes a platform 14 having a tower ormast 16 mounted on it. The tower 16 extends upwardly from the platform14 and supports a plurality of hydraulic cylinders 18. The tower 16 alsosupports a drill head 20 which is mounted for reciprocation in the tower16 upon operation of the hydraulic cylinders 18.

In the use of the automatic drilling machine 10, the drill head 20 isconnected to a drill string 22 which extends to a drill bit (not shown).The drill head 20 rotates the drill string and the drill bit and therebyforms a borehole. As the formation of the borehole progresses, the drillhead 20 moves downwardly relative to the tower 16 of the automaticdrilling machine 10.

When the drill head 20 reaches the position shown in FIG. 1, it isdisconnected from the drill string 22 and is raised relative to thetower 16 by the hydraulic cylinders 18. When the drill head 20 is at thetop of the tower 16, a new section of drill pipe is positioned under thedrill head 20 and the automatic coupling mechanism 12 of the presentinvention couples the drill head 20 to the new section of drill pipe.The new section of pipe is then connected to the drill string 22, andthe drill head 20 is again operated to rotate the drill string 22 andthe drill bit.

Referring now to FIG. 2, the automatic coupling system 12 of theautomatic drilling machine 10 is shown in detail. The system 12 includesan outer sleeve 24 which is coupled to a drive tube 26 that extendsdownwardly from the drill head 20. An inner sleeve 28 is secured to theouter sleeve 24 by a plurality of screws 30, and a retaining collar 32is threadably engaged with the distal end of the outer sleeve 24. Acompression spring 34 is mounted between the inner sleeve 28 and theouter sleeve 24.

In addition to the sleeves 24 and 28 and the spring 34, the automaticcoupling system 12 comprises a quill 36 having a threaded distal end 38.The quill 36 is mounted for sliding movement axially of the outer sleeve24, but is prevented from rotational movement relative to the outersleeve 24 by a spline connection 40. A packing nut 42 is secured betweenthe quill 36 and the inner sleeve 28 by a retaining ring 44. Thecompression spring 34 extends into engagement with the retaining ring 44and normally urges the threaded quill 36 into engagement with theretaining collar 32.

The automatic coupling system 12 further includes a quill advanceterminating subsystem 46. The subsystem 46 includes a switch actuatingplate 48 which is secured to the quill 36 by the cooperation of anannular projection 50 on the quill 36, a retaining ring 52 and aplurality of screws 54. A slider 56 is mounted adjacent the switchactuating plate 48 and includes a plate engaging roller 58. The slider56 is mounted in a guide 60 that extends from the drill head 20 and isurged toward the position shown in FIG. 2 by a tension spring 62connected between a tab 64 on the guide 60 and a tab 66 on the slider56. A limit switch 68 is mounted on the drill head 20 for actuation bythe slider 56 upon relative movement between the quill 36 and the drillhead 20.

The operation of automatic coupling system 12 is illustrated in FIGS. 2,3, 4 and 5. Referring first to FIGS. 2 and 3, a new section of drillpipe 70 is mounted beneath the drill head 20 of the automatic drillingmachine 10 and is secured with respect thereto by a suitable chuck (notshown). Thereafter, the hydraulic cylinders 18 are operated to advancethe automatic coupling system 12 toward the new section of pipe 70 and amotor and transmission assembly 72 is simultaneously actuated to rotatethe quill 36 of the system 12 relative to the new section of pipe.

Referring specifically to FIG. 2, the motor and transmission assembly 72is mounted on the drill head 20 and is coupled directly to the drivetube 26 thereof. The assembly 72 includes hydraulic motors that aredriven by hydraulic fluid supplied by v a pump 74 which is in turndriven by an engine 76. Preferably, the pump 74 and the engine 76 aremounted on a platform (not shown) positioned adjacent the drillingmachine 10 and are connected to the motor and transmission assembly 72by hydraulic piping. Hydraulic fluid for the hydraulic cylinder 18 ofthe automatic drilling machine 10 is supplied through a solenoidoperated valve 78 by a pump 80 that is driven by an engine 82.

Referring now to FIGS. 3 and 4, the quill 36 of the automatic couplingsystem 12 is advanced toward the new section of pipe 70 and issimultaneously rotated with respect thereto until the threaded end 38 ofthe quill 36 engages the new section of pipe. Interengagement of thequill 36 and the new section of pipe 70 prevents further advance of thequill 36, but does not prevent further advance of the drill head 20 andthe outer sleeve 24 connected thereto. Therefore, upon engagement withthe new section of pipe, the quill 36 moves relative to the drill head20 against the action of the spring 34.

As the quill 36 moves into the outer sleeve 24, the plate 48 engages theroller 58 of the slider 56 and thereafter moves the slider 56 upwardlyin the guide 60 against the action of the spring 62. This actioncontinues until the slider 56 engages the switch 68. Actuation of theswitch 68 operates the valve 78 to terminate operation of the hydrauliccylinders 18. Thus, actuation of the switch 68 interrupts the advance ofthe drill head 20 and thereby terminates movement of the quill 36relative to the drill head 20.

Actuation of the switch 68 does not terminate the rotation of the quill36 under the action of the motor and transmission assembly 72. Rather,the rotation of the quill 36 is continued so that the threaded end 38 ofthe quill threadably engages the new section of pipe 70 under thecombined actions of the motor and transmission assembly 72, whichrotates the quill 36, and the spring 34, which urges the quill 36 towardthe new section of pipe 70. Rotation of the quill 36 continues until athreaded connection is formed between the quill 36 and the new sectionof pipe 70 as determined by a torque monitor 84. The monitor 84comprises a pressure sensitive switch that monitors the pressure in theline between the pump 74 and the hydraulic motors of the motor andtransmission assembly 72 and that terminates the flow of hydraulic fluidto the motors when the load on the motors reaches a predetermined limit.

It will be understood that as the quill 36 is rotated into threadedinterengagement with the new section of pipe 70, the quill 36 moves awayfrom the drill head 20 under the action of the spring 34. In someinstances, this action may move the slider 56 out of engagement with thelimit switch 68. In such a case, the hydraulic cylinders 18 of theautomatic drilling machine are again actuated to advance the drill headtoward the new section of pipe 70. This action is terminated as soon asthe slider 56 reengages the switch 68.

After the quill 36 is connected to the new section of pipe, the chucksthat were engaged with the new section are released. Then the newsection is connected to the drill string and the drill head is employedto rotate the drill string and drill bit. This action increases thedepth of the borehole and is continued until the depth has increasedabout 30 feet whereupon the quill 36 is unthreaded from the drillstring, and a new section of pipe is connected between the drill stringand the drill head.

The automatic coupling system 12 of the automatic drilling machine 10also plays an important role in the unthreading of the quill 36. Becauseof the spline connection 40 between the quill 36 and the drill head 20,it is not necessary to correlate the rotary and linear movement of thequill with the lead of the threaded connection. Rather, the quill 36 issimply rotated at high speed relative to the drill string. As the quillunthreads, it moves upwardly relative to the drill head against theaction of the spring 34.

The use of an automatic coupling system employing the present inventionin an automatic drilling machine results in several advantages over theprior art. First, when the present invention is employed, it is notnecessary to accurately position a section of drill pipe relative to thedrill head. That is, since the drill head is advanced until the quillengages the pipe, the pipe can be positioned virtually anywhere when thelimits of travel of the drill head without consequence as to theoperation of the automatic coupling system.

Second, the use of the present invention eliminates the necessity ofcorrelating the advance and the rotation of the quill with the lead ofthe threaded connection. Instead, the advance and the rotation of thequill are completely independent and can be carried out at any desiredspeed. Usually, the quill is advanced much more rapidly than wouldotherwise be the case, and a threaded connection between the quill and asection of pipe is therefore formed much more quickly.

Third, when the present invention is utilized, the application ofexcessive torque loads between the quill and a section of pipe isprevented. This eliminates jamming and mutilation of threads. Also, thesubsequent unthreading of the quill is facilitated when the initialtorque on the threaded connection between the quill and a pipe sectionis held to a controlled limit.

Fourth, the automatic coupling system shown in the drawings facilitatesthe disconnection of the quill of an automatic drilling machine in thatit eliminates the necessity of correlating the rotary and linear motionsof the quill with the lead of the threaded connection during theunthreading of the quill. Thus, the use of the present inventionincreases the speed of both the coupling and the uncoupling of thequill.

Although only one embodiment of the invention is shown in the drawingsand described herein, it will be understood that the invention is notlimited to the embodiment disclosed, but is capable of rearrangement,modification and substitution of parts and elements without departingfrom the spirit of the invention.

What is claimed is:

1. An automatic coupling apparatus comprising:

a threaded member;

means for supporting and rotating the threaded member;

means for advancing the threaded member, and

means responsive to contact between the threaded member and anotherthreaded member for automatically terminating the operation of theadvancing means. 2. The automatic coupling apparatus according to claim1 wherein the terminating means comprises:

means for moving the threaded member relative to the supporting androtating means upon contact between the threaded member and anotherthreaded member, and

means responsive to the predetermined amount of relative movementbetween the threaded member and the supporting and rotating means forterminating the advance of the threaded member.

3. The automatic coupling apparatus according to claim 2 wherein themeans for moving the threaded member relative to the supporting androtating means includes a slip coupling between the threaded member andthe supporting and rotating means and means for biasing the threadedmember into engagement with another threaded member.

4. The automatic coupling apparatus according to claim 1 wherein thesupporting and rotating means supports the threaded member for movementbetween an extended position and a retracted position and means forbiasing the threaded member toward the extended position.

5. The automatic coupling apparatus according to claim 4 wherein theterminating means includes means responsive to movement of the threadedmember toward the retracted position against the action of the biasingmeans for terminating the advance of the threaded member.

6. The automatic coupling apparatus according to claim 1 furtherincluding means for terminating the rotation of the threaded member uponthreaded interengagement between the threaded member and anotherthreaded member.

7. The automatic coupling apparatus according to claim 6 wherein therotation terminating means is responsive to the torque imposed on thethreaded member by the supporting and rotating means.

8. An automatic coupling apparatus comprising:

a threaded quill;

means for positioning a drill pipe for threaded connection to the quill;

means for moving the quill into engagement with the drill pipe and forthereafter biasing the quill toward the drill pipe; and

means for rotating the quill relative to the drill pipe and therebyforming a threaded connection between the drill pipe and the quill.

9. The automatic coupling apparatus according to claim 8 furtherincluding means for terminating the rotation of the quill after thethreaded connection is formed.

10. The automatic coupling apparatus according to claim 8 wherein thequill and the rotating means are mounted on a drill head and wherein themoving and biasing means moves the drill head toward the drill pipe.

11. The automatic coupling apparatus according to claim 10 furthercharacterized by a spline coupling between the quill and the rotatingmeans for permitting relative sliding motion therebetween whilepreventing relative rotation.

12. The automatic coupling apparatus according to claim 10 wherein thequill is mounted on the drill head for sliding movement with respectthereto and wherein the biasing portion of the moving biasing meanscomprises a spring mounted between the drill head and the quill forurging the quill into engagement with the drill pipe.

13. The automatic coupling apparatus according to claim 12 furtherincluding means for terminating the movement of the drill head towardthe drill pipe in response to sliding movement of the quill relative tothe drill head.

14. The automatic coupling apparatus according to claim 13 wherein themovement terminating means includes switch means mounted for actuationupon relative movement between the quill and the drill head.

15. A method of automatically coupling a threaded quill to a drill pipecomprising:

advancing a spring loaded threaded quill toward a drill pipe andsimultaneously rotating the quill relative to the pipe;

engaging the quill with the drill pipe tocompress the spring;

actuating sensing means to terminate the advance of the quill after apredetermined amount of compression of the spring, and

actuating sensing means to terminate the rotation of the quill relativeto the drill pipe when the torque on the quill exceeds a predeterminedlevel.

16. The method according to claim 15 wherein the advancing and rotatingstep includes the steps of:

positioning a drill pipe at a predetermined location, and

moving a quill rotating mechanism toward the predetermined location.

17. The method according to claim 16 wherein the terminating stepincludes the step of sensing relative movement betweenthe quill and therotating mechanism upon engagement of the quill with the drill pipe.

18. The method according to claim 17 wherein the rotation terminatingstep includes the steps of:

sensing the torque that is applied to the quill by the rotatingmechanism, and

terminating the operation of the rotating mechanism when the torqueapplied to the quill exceeds the predetermined level.

1. An automatic coupling apparatus comprising: a threaded member; meansfor supporting and rotating the threaded member; means for advancing thethreaded member, and means responsive to contact between the threadedmember and another threaded member for automatically terminating theoperation of the advancing means.
 2. The automatic coupling apparatusaccording to claim 1 wherein the terminating means comprises: means formoving the threaded member relative to the supporting and rotating meansupon contact between the threaded member and another threaded member,and means responsive to the predetermined amount of relative movementbetween the threaded member and the supporting and rotating means forterminating the advance of the threaded member.
 3. The automaticcoupling apparatus according to claim 2 wherein the means for moving thethreaded member relative to the supporting and rotating means includes aslip coupling between the threaded member and the supporting anDrotating means and means for biasing the threaded member into engagementwith another threaded member.
 4. The automatic coupling apparatusaccording to claim 1 wherein the supporting and rotating means supportsthe threaded member for movement between an extended position and aretracted position and means for biasing the threaded member toward theextended position.
 5. The automatic coupling apparatus according toclaim 4 wherein the terminating means includes means responsive tomovement of the threaded member toward the retracted position againstthe action of the biasing means for terminating the advance of thethreaded member.
 6. The automatic coupling apparatus according to claim1 further including means for terminating the rotation of the threadedmember upon threaded interengagement between the threaded member andanother threaded member.
 7. The automatic coupling apparatus accordingto claim 6 wherein the rotation terminating means is responsive to thetorque imposed on the threaded member by the supporting and rotatingmeans.
 8. An automatic coupling apparatus comprising: a threaded quill;means for positioning a drill pipe for threaded connection to the quill;means for moving the quill into engagement with the drill pipe and forthereafter biasing the quill toward the drill pipe; and means forrotating the quill relative to the drill pipe and thereby forming athreaded connection between the drill pipe and the quill.
 9. Theautomatic coupling apparatus according to claim 8 further includingmeans for terminating the rotation of the quill after the threadedconnection is formed.
 10. The automatic coupling apparatus according toclaim 8 wherein the quill and the rotating means are mounted on a drillhead and wherein the moving and biasing means moves the drill headtoward the drill pipe.
 11. The automatic coupling apparatus according toclaim 10 further characterized by a spline coupling between the quilland the rotating means for permitting relative sliding motiontherebetween while preventing relative rotation.
 12. The automaticcoupling apparatus according to claim 10 wherein the quill is mounted onthe drill head for sliding movement with respect thereto and wherein thebiasing portion of the moving biasing means comprises a spring mountedbetween the drill head and the quill for urging the quill intoengagement with the drill pipe.
 13. The automatic coupling apparatusaccording to claim 12 further including means for terminating themovement of the drill head toward the drill pipe in response to slidingmovement of the quill relative to the drill head.
 14. The automaticcoupling apparatus according to claim 13 wherein the movementterminating means includes switch means mounted for actuation uponrelative movement between the quill and the drill head.
 15. A method ofautomatically coupling a threaded quill to a drill pipe comprising:advancing a spring loaded threaded quill toward a drill pipe andsimultaneously rotating the quill relative to the pipe; engaging thequill with the drill pipe to compress the spring; actuating sensingmeans to terminate the advance of the quill after a predetermined amountof compression of the spring, and actuating sensing means to terminatethe rotation of the quill relative to the drill pipe when the torque onthe quill exceeds a predetermined level.
 16. The method according toclaim 15 wherein the advancing and rotating step includes the steps of:positioning a drill pipe at a predetermined location, and moving a quillrotating mechanism toward the predetermined location.
 17. The methodaccording to claim 16 wherein the terminating step includes the step ofsensing relative movement between the quill and the rotating mechanismupon engagement of the quill with the drill pipe.
 18. The methodaccording to claim 17 wherein the rotation terminating step includes thesteps of: sensing the torque that is applIed to the quill by therotating mechanism, and terminating the operation of the rotatingmechanism when the torque applied to the quill exceeds the predeterminedlevel.